Field of the Invention
The present disclosure relates, in general, to a water meter and, in particular, to an ultrasonic water meter used to determine a flow rate of a fluid moving through a piping arrangement.
Description of Related Art
A flow meter, such as a water meter, is a device used to measure the volume or flow rate of a fluid being moved through a piping arrangement. Water meters are typically used to measure the volume of water consumed by residential and commercial buildings that are supplied with water by a public water supply system. Water meters may also be used at the water source or at various locations throughout the water system in order to determine the flows and flow rates delivered through that portion of the system.
There are several types of water meters that are commonly used. Selection of the required water meter is based upon different flow measurement methods, the type of the end user, the required flow rates, as well as upon measurement accuracy requirements. One type of a water meter is an ultrasonic water meter that uses an ultrasonic transducer to send ultrasonic sound waves through the fluid to determine the fluid's velocity and translate the velocity into a measurement of the fluid volume.
There are several different configurations of ultrasonic water meters that are currently used. As shown in FIG. 1, an ultrasonic water meter 10 includes a piping arrangement 11 that houses at least two ultrasonic transducers 12a, 12b for emitting an ultrasonic sound wave. By determining the travel time and speed of the ultrasonic sound wave through the fluid flow of the piping arrangement 11, an operator may determine the flow rate of the fluid moving through the piping arrangement 11. The first transducer 12a emits the ultrasonic sound wave and the second transducer 12b receives the ultrasonic sound wave. The ultrasonic sound wave is directed laterally from the first transducer 12a to a first reflective surface 13a. The first reflective surface 13a directs the ultrasonic sound wave in a horizontal/longitudinal direction to a second reflective surface 13b. The second reflective surface 13b directs the ultrasonic sound wave laterally to the second transducer 12b. A travel path 14 of the ultrasonic sound wave is substantially “U-shaped”. This ultrasonic water meter 10 is typically used in smaller residential settings. Since the ultrasonic water meter 10 utilizes a “U-shaped” travel path 14, both of the transducers 12a, 12b are positioned on the same side of the piping arrangement 11. Further, the reflective surfaces 13a, 13b are typically positioned in the center of the piping arrangement 11, which corresponds to the center of the flow. By positioning the reflective surfaces 13a, 13b in the center of the water flow, a high head loss is created in the water stream and an operator is unable to see through the interior of the piping arrangement 11 from an inlet end 15 to an outlet end 16.
As shown in FIG. 2, another ultrasonic water meter 20 includes a piping arrangement 21 that houses at least two ultrasonic transducers 22a, 22b for emitting an ultrasonic sound wave. This ultrasonic water meter 20 also provides the ultrasonic transducers 22a, 22b on the same side of the piping arrangement 21. This ultrasonic water meter 20, however, utilizes at least three reflective surfaces 23a, 23b, 23c to direct the ultrasonic sound wave through the piping arrangement 21. The first ultrasonic transducer 22a directs an ultrasonic sound wave laterally towards the first reflective surface 23a. The first reflective surface 23a directs the ultrasonic sound wave laterally at an angle towards the second reflective surface 23b. The second reflective surface 23b directs the ultrasonic sound wave laterally at an angle towards the third reflective surface 23c. The third reflective surface 23c directs the ultrasonic sound wave laterally towards the second ultrasonic transducer 22b. A travel path 24 of the ultrasonic sound wave is substantially “W-shaped”. The ultrasonic water meter 20 utilizes a first and third reflective surface 23a, 23c that do not extend as far into the flow channel of the piping arrangement 21 as compared to the first and second reflective surfaces 13a, 13b of the ultrasonic water meter 10 of FIG. 1. Therefore, there is a reduction in head loss using this ultrasonic water meter 20 and an operator may be able to see through the interior of the piping arrangement 21 from an inlet end 25 to an outlet end 26. However, this ultrasonic water meter 20 requires the use of an additional reflective surface 23b to create the travel path 24 of the ultrasonic sound wave.